Let's face it: Every inbox in the world is cluttered. From automatic emails from social networks flying in every time you're followed, Liked, pinned, or shared, to company newsletters, to the one-off email from your mother reminding you about an upcoming holiday ... your email's probably feeling pretty full right about now.

Some technology has tried to solve this problem -- apps like Mailbox and layouts like Gmail's inbox tabs have dominated the news over the past year. Some overwhelmed email users take to obsessively filtering and filing email messages on their own. Some just abandon email addresses and start fresh to avoid the deluge of email.

So as marketer, you've got a lot to compete with. When you're going up against all of these types of emails with your latest newsletter or automated workflow emails, you've really got to stand out. And the best way to do that? With a compelling, can't-help-but-click-on-this subject line. To help make your next email send successful, check out the 10 crucial components of an irresistible subject line below.

The 10 Essential Elements of a Clickable Email Subject Line

Here are a few guidelines to ensure your subject lines entice your readers to click.

1) Persona-Aware Language

Put yourself in your audience’s shoes and write your subject lines to address their needs. How do they talk about products and industries like yours? What are their biggest fears -- and how can you solve them? What language gets them fired up, and what makes them start to snooze? Your audience is unique. What may work for some email lists won't always work for your list and vice versa. Use language and messaging that they are familiar with and excited about, and start to watch your open rates skyrocket.

2) Personalization 

Make your email recipients think you are talking right to them with personalized content. Include their first names (it could increase clickthrough rates), or even add something about their specific location. You don't want to go overboard here (no one likes to feel like a company is stalking them), but these little personalized touches show that you know more about them than their email address.

3) Action-Oriented Verbs

Use action verbs to inspire your readers to click. You want your verbs to inspire your audience to click on your email by instilling urgency and excitement for people reading your subject lines. For example, in an email inviting people to a hockey legend dinner, the email subject line should read, “Dine with Bruins legend Bobby Orr”, rather than a more generic (and less actionable) “Local Boston Sports Legend Meal”. The former email uses “Dine” to help the reader envision themselves at a dinner table.

4) Timeliness

Beyond getting people to want to take action in the first place, you want to inspire people to take action now with your subject line. For instance, if you wanted to make the subject line from the last example even better, you could add "Dine with Bruins legend Bobby Orr this Saturday." Because you tell your subscribers exactly when they can dine with Bobby Orr -- and it's coming up soon -- they will be more inclined to open the email. They don't want to miss out!

5) An Exclusive Value Proposition 

Always let your subscribers know what they're going to get in the email before they even open it. For example, the subject line “[Free Collection] 101 Companies Rocking Social Media” tells readers exactly what they will get by opening the email: a free download featuring 101 companies rocking social media. Similarly, if you are running a promo, like a 20% off special, allude to that specific number in the first third of your subject line so your subscribers know why they should open your emails.

6) Clarity

MarketingExperiments is often quoted as saying “clarity trumps persuasion” when writing online copy. A clear, easily-understandable subject line is vital for generating email clickthroughs. Occasionally, when marketers try too hard to be clever, they end up just making the reader think “huh?” You want your emails to grab attention, but not at the expense of clearly conveying the email’s content.

7) Brevity 

Email subject lines will get cut off if they’re too long, particularly on mobile devices. We recommend using subject lines with fewer than 50 characters to make sure readers scanning their emails will read the entire subject line. Most subscribers won't click through just to find out what was after the ellipses in a cut-off subject line.

8) Consistency

Your email subject line is making a promise to your reader about what you will deliver in your message. Make sure that you make good on that commitment. Do not promise a 50% off coupon in your subject line unless that coupon is prominently displayed in your email. Similarly, don’t advertise 50% off if that discount only applies to a small segment of your products. A “bait-and-switch” email breeds too much distrust to be worthwhile. If people think they have been cheated by your subject lines, they will stop opening your emails, which leads to lower open-, clickthrough-, and conversion rates, as well as higher unsubscribes. No good.

9) Avoid SPAM triggers

Email spammers rely heavily on certain words to boost their open rates. Because of these sneaky practices, email providers use special spam filters to keep out any emails containing certain words. Email marketers should be careful about using words like “Cash,” “Quote,” and “Save” to make sure they don’t inadvertently get caught by a spam trap. Don't want to get caught in a trap? Check out this blog article that includes a full list of spam trigger words.

Spam traps look at more than just subject lines to determine if they will deliver your email. For example, “Free” is a traditionally spammy subject line word, but you will notice that we included it in our “101 Companies Rocking Social Media” subject line. We did a lot of background research to make sure this word wouldn’t work against us. Because HubSpot has a great sender reputation, and we were sending out an email from a real person, including “free” in this line didn’t impact the email’s deliverability. There are several tools online you can use to test if your subject lines will raise any red flags.

10) Optimized Sender and Preview Text

Okay, okay, I know that this isn't technically in the subject line, but these are crucial elements to your email being opened because the "from" field, the subject line, and the preview text all hang out on the same line in your inbox. They deserve your attention, too!

The key to optimizing your sender is to make it something that is easily recognizable to your subscribers so they want to open it -- whether that's a name of someone in your company or your company itself depends on your list, but the key is to have it be recognizable so people continue to open your emails. 

The preview text is a little easier -- it should be something that follows up to your subject line. Maybe it answers your subject line's question, or just follows along with the same theme. For example, check out this awesome preview from BuzzFeed's email:


Pretty funny, right? It definitely made me click through.

So get creative with your "From" field and preview text -- it could be the difference between someone opening your emails and just letting them rot in their inbox.

Want to continue to dissect the anatomy of top-notch emails? Download our guide to creating a five star email here.

Image credit: 10ch

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Originally published Sep 23, 2013 8:00:00 AM, updated August 25 2017


Email Subject Lines